Table 1 Matrix for BBD with real and coded values of three independent variables along with the resulted responses of pigment production in term (mg/L)
| Â | Variables | Pigment conc. (mg/L) | ||||
|---|---|---|---|---|---|---|
Trial | X1 | X2 | X3 | Experimental | Predicted | Residual* |
1 | 0 | 0 | 0 | 3.44 | 3.38 | 0.06 |
2 | 0 | 0 | 0 | 3.37 | 3.38 | − 0.01 |
3 | 0 | -1 | 1 | 2.75 | 2.50125 | 0.24875 |
4 | 0 | 1 | -1 | 4.2 | 4.44875 | − 0.24875 |
5 | − 1 | − 1 | 0 | 3.19 | 3.54125 | − 0.35125 |
6 | 0 | 0 | 0 | 3.33 | 3.38 | − 0.05 |
7 | 1 | 0 | − 1 | 3.8 | 3.9025 | − 0.1025 |
8 | 0 | 1 | 1 | 3.7 | 4.19625 | − 0.49625 |
9 | 0 | − 1 | − 1 | 2.8 | 2.30375 | 0.49625 |
10 | − 1 | 0 | 1 | 4.24 | 4.1375 | 0.1025 |
11 | − 1 | 0 | − 1 | 3.34 | 3.485 | − 0.145 |
12 | 1 | 0 | 1 | 3.34 | 3.195 | 0.145 |
13 | 1 | 1 | 0 | 5.55 | 5.19875 | 0.35125 |
14 | 1 | − 1 | 0 | 2.63 | 3.02375 | − 0.39375 |
15 | − 1 | 1 | 0 | 5.6 | 5.20625 | 0.39375 |
Variables | Coded level and actual level | ||
|---|---|---|---|
|  | − 1 | 0 | 1 |
X1: % MgSO4 (w/v) | 0.1 | 0.3 | 0.5 |
X2: % Whey (v/v) | 40 | 70 | 100 |
X3: %Inoculum size (v/v)* | 5 | 10 | 15 |